Submission #636208

#	Time	Username	Problem	Language	Result	Execution time	Memory
636208		Yazan_Alattar	Jail (JOI22_jail)	C++14	0 / 100	6 ms	9728 KiB

jail

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
#define F first
#define S second
#define pb push_back
#define endl "\n"
#define all(x) x.begin(), x.end()
const int M = 200007;
const ll inf = 1e9;
const ll INF = 1e18;
const ll mod = 1e9 + 7;
const double pi = acos(-1);
const double eps = 1e-6;
const int dx[] = {0, -1, 0, 1}, dy[] = {1, 0, -1, 0};
const int block = 320;

vector <int> adj[M], to[M];
int n, m, s[M], t[M], dep[M], anc[M][30], in[M], st[M], out[M], timer;

bool con(int i, int j){
    return st[i] <= st[j] && out[i] >= out[j];
}

int lca(int x, int y){
    if(x == y) return x;
    if(dep[x] > dep[y]) swap(x, y);

    for(int i = 18; i >= 0; --i) if(dep[anc[y][i]] >= dep[x]) y = anc[y][i];
    if(x == y) return x;

    for(int i = 18; i >= 0; --i) if(anc[x][i] != anc[y][i]){
        x = anc[x][i];
        y = anc[y][i];
    }

    return anc[x][0];
}

bool check(int i, int j){
    if(!con(s[i], s[j]) && !con(t[i], s[j]) && con(lca(s[i], t[i]), s[j])) return 0;
    if(!con(s[j], t[i]) && !con(t[j], t[i]) && con(lca(s[j], t[j]), t[i])) return 0;
    return 1;
}

void dfs(int node, int par){
    st[node] = ++timer;
    for(auto i : adj[node]) if(i != par){
        dep[i] = dep[node] + 1;
        anc[i][0] = node;
        dfs(i, node);
    }
    out[node] = ++timer;
    return;
}


int main(){
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    int q;
    cin >> q;
    while(q--){
        cin >> n;
        for(int i = 1; i < n; ++i){
            int x, y;
            cin >> x >> y;
            adj[x].pb(y);
            adj[y].pb(x);
        }

        dep[1] = 1;
        dfs(1, 0);

        for(int j = 1; j < 19; ++j)
            for(int i = 1; i <= n; ++i)
                anc[i][j] = anc[anc[i][j - 1]][j - 1];

        cin >> m;
        for(int i = 1; i <= m; ++i) cin >> s[i] >> t[i];

        for(int i = 1; i <= m; ++i){
            for(int j = 1; j <= m; ++j){
                if(i != j && !check(i, j)) to[j].pb(i), ++in[i];
            }
        }

        queue <int> q;
        for(int i = 1; i <= m; ++i) if(!in[i]) q.push(i);

        int cnt = 0;
        while(!q.empty()){
            int node = q.front();
            q.pop();
            ++cnt;

            for(auto i : to[node]){
                --in[i];
                if(!in[i]) q.push(i);
            }
        }

        cout << (cnt != m ? "No\n" : "Yes\n");

        for(int i = 1; i <= n; ++i){
            adj[i].clear();
            to[i].clear();
            in[i] = 0;
        }
    }

    return 0;
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 5
• Subtask 3: 0 / 16
• Subtask 4: 0 / 28
• Subtask 5: 0 / 12
• Subtask 6: 0 / 11
• Subtask 7: 0 / 23